Marcellus indicated a shallow arch within the bricks, just above head height. “Remove the bricks below the arch, please, Apprentice. They should come out quite easily.”

Septimus sighed and got to work. He was pleased to find that the bricks did indeed come away easily.

“Alchemist’s mortar—never sets,” said Marcellus. “It began as a mistake when we had to do a lot of building ourselves. Looks solid, but is as soft as butter. Very useful at times.”

Septimus took away the rest of the bricks below the arch. Behind them was a black shiny surface reflected in the flames of the Fyre Globe.

Marcellus smiled. “I understand you have seen something like this before.”

Septimus looked suspicious. “It’s not some kind of Time Glass, is it?” he asked.

Marcellus looked guilty. “Oh, dear. I am so sorry about the way we met, Apprentice. It was, I see now, very wrong. You do know I would never do that again, do you not?” Marcellus picked up the chisel, counted down from the top brick on the right-hand side of the doorway. He levered out the seventh brick and placed his hand on the smooth black substance behind it. A faint green light began to glow beneath it.

Septimus stared at it, astonished.

“You recognize it, Apprentice?” Marcellus smiled.

“Is . . . is this a moving chamber?”

“Indeed it is.”

“Like the one on the Isles of Syren?”

“Pretty much. Unfortunately I cannot remember the finer details of its operation. I used to know it, but like many memories, it has faded. I was hoping you might remember. I would like to get it working again. So much more pleasant than the long climb down.”

“To the Chamber of Fyre?”

“To the Chamber of Fyre. So, Apprentice. Shall we go?”

Gingerly Septimus stretched out his hand and placed his palm on the opening plate—the worn part of the smooth, cool surface behind the brick. The green light sprang up below once again; it grew bright and then began to fade.

“Oh,” said Septimus. “That shouldn’t happen.” He took his hand away and rubbed it on his tunic; then he put it back and leaned his whole weight against the surface. This time the green light immediately glowed bright and suddenly, silently, a concealed oval door slid open revealing a tiny, blue-lit chamber.

“Oh, well done!” said Marcellus, excited. “Shall we step inside?”

Septimus followed Marcellus through the door into a virtually spherical space. Its walls were a smooth, shiny black material with no obvious features. It was, as far as Septimus could tell, identical to the one he had known on the Isles of Syren.

“Perhaps you would like to close the door, Apprentice?”

Septimus was not sure that he would. “Marcellus, when did you last use this?” he asked.

Marcellus looked surprised. “Oh, goodness. Well, it’s all a bit of a blur, really. There was a lot going on at the time. Esmeralda was with me; I remember that.”

“So, about four hundred and seventy-five years ago?”

“About that, I suppose.”

For someone who had dabbled in moving from one Time to another, Marcellus was always annoyingly vague about time, Septimus thought. “I’m asking because Syrah said that it needed to be used every day to keep it, er, alive.”

“Alive!” Marcellus laughed. “Superstitious nonsense. It is a piece of machinery.”

“I know,” said Septimus, “but that was how she explained it. And it makes sense to me. She said its life drained away unless it was . . . what was the word she used? Recharged.”

Marcellus was skeptical. “Septimus, you must remember that Syrah was Possessed. She was just saying words like a . . . Oh, what are those birds with many colors?”

“Parrots. Syrah was not like a parrot,” said Septimus, annoyed.

“No, of course not. Not the real Syrah,” Marcellus said soothingly. “However, I can assure you that this chamber is not alive.”

Septimus felt that it would be wrong to back out now. There was a worn spot beside the door, and he placed his palm onto it. A red light glowed beneath, lighting up his hand, and the door closed silently. A small orange arrow pointing downward now appeared on the other side of the chamber. Septimus went over to it and reluctantly raised his hand to press it. “Are you sure about this?” he asked.

“Yes,” said Marcellus. “Of course I am.”

Taking a deep breath, Septimus placed his hand on the orange arrow and pressed. The floor of the chamber gave a sickening lurch and his stomach did the same. The chamber was falling fast and Septimus had forgotten just how terrifying it was. When he had been in the one on the Isles of Syren, he had been with Syrah, and she had known what she was doing. Now he was with Marcellus, who looked just as scared as he was. Septimus watched the orange arrow plummeting down the wall, like a bird hit by a stone.